The present invention relates to fiber optic cables that include at least one optical transmission component and at least one strength component.
Fiber optic cables include at least one optical fiber that can transmit data, computer, and/or telecommunication information. Conventional cable designs, however, can have unacceptable optical performance characteristics, and/or can require undesirable structural features that make optical fiber access difficult. In addition, conventional cables can be difficult to route through cable passageways, and/or can make the cable expensive to produce.
Cable designs that define a backdrop for the present inventions can be, for example, difficult to route through cable passageways and/or can be expensive to produce. U.S. Pat. No. 5,155,304 discloses an aerial service wire that includes a PVC jacket having a generally block-shaped cross section. Enclosed by the jacket are two groups of strength components, each of which includes a plurality of filaments that are impregnated with a plastic material. Moreover, conventional aerial fiber optic cables can be too large for some applications. For example, EP-A1-0629889 discloses an aerial cable requiring an optical cable central part with two metallic strain relief elements that are placed diametrically opposite to each other and adjacent the optical cable part. The strain relief elements are connected to the cable part by means of a jacket that includes web-like extensions between the optical cable part and the strain relief elements. In addition, optical cables of the single fiber type may not provide adequate data transmission capacity. For example, JP-A-8304675 discloses a single optical fiber disposed between two glass fibers having respective outside diameters that are larger than the outside diameter of the optical fiber. Moreover, the two relatively large glass fibers can make the cable stiff and difficult to route through cable passageways.
The present invention is directed to a fiber optic cable having at least one optical transmission component with a nominal radius, and at least two strength components, at least one of the strength components being generally adjacent to the optical transmission component. At least one of the strength components can have a nominal radius that is less than the nominal radius of the optical transmission component. The cable has a cable jacket surrounding the optical transmission component and the strength components. The optical transmission component being generally disposed adjacent generally flat surfaces on the cable jacket.
The present invention is also directed to a fiber optic cable with at least one optical transmission component, and at least two strength components, the strength components being disposed adjacent the optical transmission component. The cable has a jacket surrounding the optical transmission component and the strength components. The cable jacket being about 10 mm wide or less and about 5 mm in height or less.
The present invention also includes an extrusion tooling apparatus comprising a tip and a die, the extrusion tooling apparatus being operative to extrude jacketing compound about strength components and at least one optical transmission component for making a generally flat cable. The extrusion tooling apparatus includes an inlet port for receiving a jacketing compound under suitable temperature and pressure conditions, channels for channeling the jacketing compound from the inlet port toward the tip and the die. The tip has an orifice defined within an end portion of the tip for receiving the strength and optical transmission components therein, the tip includes at least two generally flat and generally parallel surfaces on opposite sides of the tip. The tip further includes arcuate sections. The arcuate sections generally complement said shape of said strength components. The die includes a die orifice for shaping the jacketing compound as it exits said extrusion-tooling apparatus.